Canon global

High-Resolution, High-Sensitivity, Low-Noise Image Sensor

The CMOS sensor is one of the key components of a digital SLR camera. Canon conducts development and production of CMOS sensors using proprietary technologies. Canon currently uses two different sizes of CMOS sensor: 35 mm full-frame and APS-C.
Canon's CMOS sensors feature large size and high resolution^*1 (Up to approximately 22.3 million pixels with a 35 mm full-frame CMOS sensor), excellent sensitivity (low noise), and a wide dynamic range. Featuring sixteen-channel signal reading, as well as compatibility with high-speed continuous shooting of approximately 14 frames per second and full HD movies supported by DIGIC, Canon's CMOS sensors facilitate new levels of still photo and movie expression that far surpass those of film cameras.

35 mm Full-Frame CMOS Sensor

• *1 Resolution
  The effective pixels of CMOS sensors are as follows.

Realization of Comfortable and Speedy Shooting Using a System Approaching Eyesight

New Area Autofocus System

The autofocus (AF) technology of Canon's EOS series of SLR cameras debuted in 1987, making an impact on the market with its speed and ease of use. Since that time, Canon has continued to develop and evolve AF technology into a digital camera legacy: from its initial AF with a single focus point at the center of the viewfinder to 3-point AF in 1990, 5-point AF in 1992, 45-point AF in 1998 and 61-point Area AF in 2012.

Area AF Sensor

61-Point High-Density Reticle AF

The 45-point Area Autofocus, a standard feature in SLR cameras for professional photographers, has now evolved to 61-point Area Autofocus. The dense array of 61 focus points in the AF frame measures the distance from the subject with pinpoint accuracy through 5 dual-cross- type points for f/2.8 and f/5.6 lenses or 41 cross- type points for f/4 lenses. This evolution is now available with the EOS-1D X and EOS 5D Mark III flagship models.

63-Zone Dual-Layer Metering Sensor

The exposure of the subject is determined by the metering sensor. Canon has developed a new 63-zone Dual-layer Metering Sensor with a dual-layer photo sensor. The first layer measures blue-green light and the second layer measures green-red light. By providing functionality for individually measuring the intensity of red and blue wavelengths of RGB primary colors (color information), this automatically and accurately corrects exposure errors caused by the type of light source. This reflects the actual color of the subject and the changing color information of the subject under artificial light, etc. in exposure to complement the camera's exposure characteristics. This eliminates subtle variations in exposure caused by color. The subject area is also detected based on autofocus information, and stable exposure with emphasis placed on the main subject is achieved through a metering algorithm utilized in computing evaluation metering.

Conceptual View of 63-zone Dual-layer Metering

New AF System for High-Speed, High-Precision Focus

Canon has developed ‘Hybrid CMOS AF', an advanced autofocus technology to enhance the focusing speed for Live View photography and movie shooting.
Hybrid CMOS AF is a combination of the phase-difference method for faster focusing and the contrast method for higher accuracy. The picture element embedded in the CMOS sensor (focal plane) designed for phase-difference AF quickly measures the subject distance, then the contrast AF focuses with extreme accuracy. This realizes much faster and more precise focusing than the AF systems of former models.

Phase-Difference AF

The phase-difference AF method works by dividing the incoming subject image that passes through the photographic lens into two images and then detecting the difference in the focus point position between the two images. The original image is split into two images with two secondary microlens arrays in the AF sensor unit. Two line sensors measure each focus point.
The lens moves forward or backward depending on whether the focal point is in front of the subject (closer to the camera), or behind the subject (farther away from the camera). Because the camera can immediately figure out the direction and amount to move the lens, phase-difference AF can focus very quickly.

Principles of Phase Difference AF Method

Contrast AF

Because the contrast is highest when the image is in correct focus, the camera analyzes the contrast information from the image on the imaging sensor and moves the lens to the position that gives the maximum contrast value.The drawback with contrast AF is that the lens must traverse the full focusing range for finding the peak contrast location. This requires more time to reach focus, but results in higher focus accuracy. Contrast AF method is commonly employed on most video cameras, TV cameras, and compact digital cameras.

Principles of Contrast AF Method

Lens Coating Technology Created by Nanotechnology

The reflection of light from the lens surface causes flare and ghosting. In the past, the surface was coated with a thin film to control reflected light, but it could not be sufficiently controlled in some cases depending on the angle of incident light.
SWC developed by Canon is a new type of technology for preventing reflection by using an array of countless wedge-shaped nanostructures smaller than the wavelength of visible light arranged on the lens surface to control the reflection of light. As there is a smooth transition between the refractive indexes of glass and air, it is possible to eliminate the boundary between substantially different refractive indexes, which enables significant control over the occurrence of reflected light. It is also very effective with light that has a large angle of incidence, which could not be controlled using conventional coating.

SWC Structure

Realizing Smaller, Lighter Telephoto Lenses

Canon developed the world's first Diffractive Optics (DO) lens to eliminate chromatic aberrations,^*2 which occur in opposite directions in diffractive and refractive optical elements. The unique two-layer DO lens takes advantage of this phenomenon, and is formed by placing two precise diffraction gratings a few micrometers^*3 apart on the surface of glass lenses to create a multi-layer structure.

Correcting Chromatic Aberrations with a DO Lens

Canon incorporated the lens into its EF400mm f/4 DO IS USM interchangeable lens for SLR cameras, significantly reducing the size and weight of telephoto lenses while maintaining their high imaging performance. Next, the company conducted an even more thorough study of the materials and shape of the diffraction gratings, developing a three-layer DO lens that utilizes three diffractive optical elements. Incorporating the three-layer DO lens into the EF70-300mm f/4.5-5.6 DO IS USM zoom lens, Canon also successfully reduced the size of telephoto zoom lenses.

• *2 Chromatic aberration
  One factor that can negatively affect image quality is color blur, or chromatic aberration, caused by wavelength-induced fluctuations in the refractive index of light passing through a lens. Ordinarily, this problem is corrected by using multiple convex and concave lenses in combination.
• *3 Micrometer (μm) : 1 μm = one millionth of a meter